How Quantum Computers Use Special Devices to Control Qubits

This patent describes a way for quantum computers to control special quantum bits, called topological qubits, using a "partial interferometric device" to perform specific operations.

What it covers

This patent describes a quantum computer design that uses a "partial interferometric device" to perform operations on "topological qubits" (Claim 1, 10, 16). This device can generate single qubit gates, like a "θ/2 phase gate" (Claim 2, 4), or "entangling gates" for multiple qubits (Claim 5). The core idea is to position specific "target quasiparticles" of the qubit within a central region of the interferometric device (Claim 3, 11). For example, a quantum computer could use a "Fabry-Pérot double point contact interferometer" (Claim 12) to apply a "π/8 phase gate" to a topological qubit made of "Majorana zero mode quasiparticles" (Claim 7, 8, 20).

What it doesn't cover

• —Does not cover quantum operations that do not use a "partial interferometric device" as described.
• —Does not cover quantum computers that only use non-topological qubits.
• —Does not cover qubits formed from quasiparticles other than "Ising-type" or "Majorana zero mode" quasiparticles.
• —Does not cover quantum gates that are not "phase gates" or "qubit operators" applied by the partial interferometric device.
• —Does not cover interferometric devices that are not "partial" or do not include a "Fabry-Pérot double point contact interferometer."

The clever bit

The clever bit is using a "partial interferometric device," specifically a "Fabry-Pérot double point contact interferometer," to precisely manipulate "topological qubits." This allows for the application of specific quantum operations, like phase gates, in a way that can complement "topologically protected quantum gates" within a larger quantum computer architecture, offering a path to more robust quantum computation.

Why it matters

This patent is significant for the field of topological quantum computing, a promising approach to building quantum computers that are inherently more resistant to errors. By describing specific mechanisms for controlling topological qubits using "partial interferometric devices," it contributes to the foundational technology needed to build fault-tolerant quantum computers. This area of research aims to overcome a major hurdle in quantum computing: the fragility of qubits.

Real-world examples

• 1.Microsoft's research into topological quantum computing
• 2.Experimental setups for Majorana zero mode detection
• 3.Quantum computing architectures exploring fault tolerance
• 4.Devices using 5/2 Quantum Hall systems or topological superconductors